Dosage control syringe

Abstract

A dosage control syringe includes a barrel, a plunger, an adjustable lock member supported along a guide (such as a track) that is disposed along or outside an outer wall of the syringe barrel, and a stop member coupled to the plunger or the lock member. The stop member is generally aligned between the adjustable lock member and a portion of the plunger so as to limit or preclude further movement of the plunger upon engagement of the stop member with both the lock member and the plunger. The plunger is stopped by the lock member, via the stop member, when the plunger has traveled a predetermined distance set by the lock member, the distance corresponding to a desired dosage of fluid from the syringe.

The invention claimed is: 
     
       1. A syringe comprising:
 a barrel defining a fluid chamber and having a longitudinal axis; 
 a plunger at least partially disposed in said fluid chamber of said barrel and having a sealing member for slidably and sealingly engaging said barrel, said plunger having a plunger flange extending outwardly away from the longitudinal axis and laterally outboard of said barrel; 
 an elongate guide disposed along said barrel; 
 an adjustable lock member movably disposed along said elongate guide; 
 a stop member coupled to one of said adjustable lock member and said plunger flange and aligned so as to selectively contact the other of said adjustable lock member and said plunger flange; and 
 wherein when said plunger is moved sufficiently so that said stop member contacts said other of said adjustable lock member and said plunger flange, further movement of said plunger relative to said barrel is substantially precluded. 
 
     
     
       2. The syringe of  claim 1 , wherein said lock member is configurable between a locking configuration in which said lock member lockably engages said elongate guide, and a movable configuration in which said lock member is movable along said elongate guide. 
     
     
       3. The syringe of  claim 2 , wherein said elongate guide comprises a track having plurality of ratchet teeth and said lock member comprises a tooth-engaging projection, said tooth-engaging projection being operable to selectively engage at least one of said ratchet teeth wherein said lock member lockably engages said track, and to selectively disengage said ratchet teeth wherein said lock member is movable along said track. 
     
     
       4. The syringe of  claim 3 , wherein said lock member comprises a trigger release operable to disengage said tooth-engaging projection from said ratchet teeth of said track. 
     
     
       5. The syringe of  claim 3 , wherein said plurality of ratchet teeth are evenly spaced from one another in a manner that corresponds to fixed-increment volumetric changes of said fluid chamber when said plunger is moved so that said stop member contacts said other of said adjustable lock member and said plunger flange. 
     
     
       6. The syringe of  claim 3 , wherein said stop member comprises a tubular member attached to said adjustable lock member, said tubular member receiving said track in a telescoping manner. 
     
     
       7. The syringe of  claim 1 , wherein said barrel comprises an outer surface and wherein said elongate guide is established along said outer surface. 
     
     
       8. The syringe of  claim 1 , wherein said barrel comprises a double-wall barrel having an outer wall spaced outwardly from an inner wall, said inner wall comprising an inner surface defining said fluid chamber, and said outer wall comprising an outer surface. 
     
     
       9. The syringe of  claim 8 , wherein said guide is established along said outer surface of said outer wall. 
     
     
       10. The syringe of  claim 8 , wherein said guide is established along an outer surface of said inner wall, and wherein said outer wall comprises a slot for receiving said guide and/or said adjustable lock member. 
     
     
       11. The syringe of  claim 1 , wherein said outer wall of said barrel comprises indicia indicative of dosage. 
     
     
       12. The syringe of  claim 11 , wherein said indicia are generally aligned with said elongate guide. 
     
     
       13. The syringe of  claim 1 , wherein said barrel comprises a barrel flange extending generally perpendicular to the longitudinal axis, said barrel flange comprising an opening for receiving said stop member of said plunger, and wherein said stop member moves through said opening of said barrel flange as said plunger travels along said barrel. 
     
     
       14. The syringe of  claim 1 , wherein said barrel comprises a barrel flange extending generally perpendicular to the longitudinal axis, said barrel flange comprising an opening for receiving said stop member of said plunger, and wherein said stop member moves through said opening of said barrel flange as said adjustable stop member moves along said elongate guide. 
     
     
       15. The syringe of  claim 1 , further comprising at least one chosen from a hypodermic needle and a nozzle in communication with said fluid chamber for directing a fluid out of said fluid chamber. 
     
     
       16. The syringe of  claim 1 , wherein said stop member is coupled to said adjustable lock member and is configured to be engaged by an upper surface of said plunger flange when said plunger is withdrawn a distance from said barrel corresponding to a preselected volume of said fluid chamber. 
     
     
       17. A syringe comprising:
 a barrel having a longitudinal axis, an outer surface, and an inner surface, said inner surface defining a fluid chamber, said outer and inner surfaces spaced outwardly from the longitudinal axis; 
 a plunger having first and second opposed end portions, said first end portion disposed in said fluid chamber of said barrel and having a sealing member disposed at said first end portion, said sealing member slidably and sealingly engaging said inner surface of said barrel, said second end portion having a plunger flange, said plunger flange extending outwardly away from the longitudinal axis; 
 an elongate guide disposed outboard of said inner surface of said barrel and aligned generally parallel with the longitudinal axis; 
 an adjustable lock member movably disposed along said elongate guide; 
 a stop member disposed outboard of said outer surface of said barrel and aligned generally parallel with the longitudinal axis, said stop member coupled to one of said adjustable lock member and said plunger flange and aligned so as to selectively contact the other of said adjustable lock member and said plunger flange; and 
 wherein when said plunger is moved sufficiently so that said stop member contacts said other of said adjustable lock member and said plunger flange, further movement of said plunger relative to said barrel is substantially precluded. 
 
     
     
       18. The syringe of  claim 17 , wherein said lock member is configurable between a locking configuration in which said lock member lockably engages said elongate guide, and a movable configuration in which said lock member is movable along said elongate guide. 
     
     
       19. The syringe of  claim 18 , wherein said elongate guide comprises a track having plurality of ratchet teeth and said lock member comprises a tooth-engaging projection, said tooth-engaging projection being operable to selectively engage at least one of said ratchet teeth wherein said lock member lockably engages said track, and to selectively disengage said ratchet teeth wherein said lock member is movable along said track. 
     
     
       20. The syringe of  claim 19 , wherein said lock member comprises a trigger release operable to disengage said tooth-engaging projection from said ratchet teeth of said track. 
     
     
       21. The syringe of  claim 17 , wherein said elongate guide is established along said outer surface of said barrel. 
     
     
       22. The syringe of  claim 17 , wherein said barrel comprises a double-wall barrel having an outer wall spaced outwardly from an inner wall, said inner wall comprising said inner surface defining said fluid chamber, and said outer wall comprising said outer surface. 
     
     
       23. The syringe of  claim 22 , wherein said guide is established along said outer surface of said outer wall. 
     
     
       24. The syringe of  claim 22 , wherein said guide is established along an outer surface of said inner wall, and wherein said outer wall comprises a slot for receiving said guide and/or said adjustable lock member. 
     
     
       25. The syringe of  claim 17 , wherein said outer wall of said barrel comprises indicia indicative of dosage. 
     
     
       26. The syringe of  claim 25 , wherein said indicia are generally aligned with said elongate guide. 
     
     
       27. The syringe of  claim 25 , wherein said lock member comprises an indicator that aligns with said indicia to indicate the dosage corresponding to the position of said lock member on said elongate guide. 
     
     
       28. The syringe of  claim 17 , wherein said barrel comprises a barrel flange extending generally perpendicular to the longitudinal axis, said barrel flange comprising an opening for receiving said stop member of said plunger, and wherein said stop member moves through said opening of said barrel flange as said plunger travels along said barrel. 
     
     
       29. The syringe of  claim 28 , wherein said barrel flange comprises a support tube defining said opening and supporting said stop member of said plunger to limit buckling or flexing of said stop member. 
     
     
       30. The syringe of  claim 17 , further comprising at least one chosen from a hypodermic needle and a nozzle in communication with said fluid chamber for directing a fluid out of said fluid chamber.